We perform ray and wave simulations of passive and active spiral-shaped optical microcavities, comparing our results to experimental data obtained with mid-infrared quantum cascade spiral microlasers. Focusing on the angular emission characteristics, we find that both ray and wave simulations are consistent with the experimental data, showing richly-featured, multidirectional far-field emission...

In KGd(1-x)Lu(x)(WO(4))(2):Yb(3+) channel waveguides grown onto KY(WO(4))(2) substrates by liquid phase epitaxy and microstructured by Ar+ beam etching, we produced 418 mW of continuous-wave output power at 1023 nm with a slope efficiency of 71% and a threshold of 40 mW of launched pump power at 981 nm. The degree of output coupling was 70%. By grating tuning in an extended cavity and pumping a...

The operational characteristics of a novel continuous-wave compact intracavity singly-resonant optical parametric oscillator pumped by a vertical external cavity surfaceemitting laser are numerically analyzed. Keywords—nonlinear frequency conversion; semiconductor laser; intracavity optical parametric oscillator Continuous-wave optical parametric oscillators (OPOs) take up a distinguished niche...

An optically pumped ZnO nanowire laser with a 10-period SiO2/SiNx distributed Bragg reflector (DBR) was demonstrated. Stimulated emissions with equally distributed Fabry–Pérot lasing modes were observed at pumping powers larger than 121 kW/cm2. This result, when compared to nanowires of the same length and without a DBR structure, shows that a lower threshold of pumping power, higher quality fa...

We report on a novel resonantly-pumped, erbium (Er)-based, gas-cooled disk laser (GCDL) scalable to highaverage power (HAP). The GCDL uses edge-pumped composite laser disks known for their near perfect pump uniformity and compact configuration. Edge pumping enables a long path for pump absorption, which permits using low Er concentration and limits upconversion losses. Resonant operation reduce...

We report the generation of high-repetition-rate femtosecond pulses in the blue by intracavity doubling of a mode-locked Ti:sapphire laser using ,f-BaB204. To reduce the pulse-broadening effect of group-velocity mismatch, an extremely thin p-BaB204 crystal is used. By pumping the Ti:sapphire laser with 4.4 W of power from an Ar' laser, as much as 230 mW of 430-nm light is produced at a 72-MHz r...

We describe an array of spin-exchange-relaxation-free optical magnetometers designed for detection of fetal magnetocardiography (fMCG). The individual magnetometers are configured with a small volume with intense optical pumping, surrounded by a large pump-free region. Spin-polarized atoms that diffuse out of the optical pumping region precess in the ambient magnetic field and are detected by a...

One technique for measuring the fraction of molecules pumped to the excited state in stimulated Raman pumping (SRP) is to record the depletion of molecules in the lower state by resonance enhanced multiphoton ionization (REMPI). The presence of electric fields on the order of 10(7) V/cm arising from the pulsed SRP laser beams is sufficient to shift the line position of the REMPI transition to s...

An X-ray preionised, discharge excited ArF excimer laser, = 193 nm, has been studied in the long pulse regime. The laser performance is found to be primarily dependent on the discharge stability, and therefore, on the gas composition, preionization timing and the pumping power. Using X-ray preionization and prepulse-mainpulse excitation, laser pulselengths of up to 120-ns full-width at half-max...

A laser driven electron x-ray source (LEXS) using a high repetition rate, terawatt laser system is described. The laser system has adopted design features that make it more suitable for the generation of hard x-ray pulses. These features include a simplified pumping scheme to reduce cost and complexity, a λ/4 broadband regenerative amplifier to support high-energy, short optical pulse generatio...